docs: def compute_bounds(feed: "Feed") -> Tuple:
      """
      Return the tuple (min longitude, min latitude, max longitude,
      max latitude) where the longitudes and latitude vary across all
      the Feed's stop coordinates.
      """
      lons, lats = feed.stops["stop_lon"], feed.stops["stop_lat"]
      return lons.min(), lats.min(), lons.max(), lats.max()